The invention herein is a fastening device for aiding in the process of securing sheets of longitudinally extending rubber roofing to the upper surface of a roof. In this regard, roofing sheets made of rubber material are now used more widely for roof coverings because of the durability. However, this invention is also applicable to other types of roof coverings.
The general approach is to place over the upper roof surface a series of rubber roof sheets so that they encompass the entire upper roof surface as a complete covering. In many applications, strategically placed bonding plates are affixed over the top of the rubber roof sheets to secure the rubber roof sheets in a flush manner to the upper roof surface. A usual arrangement in using such fastening plates is a series of evenly-spaced rows and columns of such plates, regularly and symmetrically spaced as seen from an upper elevational view. Bonding plates function to securely hold the rubber roofing sheets in place with the aid of a fastening device such as a longitudinally extending screw-like or nail-like member forcibly thrust downwardly through the horizontally disposed bonding plate into the roof deck or fixed roof structure. Thus, the present practice, as stated, is to disperse the bonding plates over the upper roof surface, using nails or screws, to adhere the bonding plate firmly against the upper surface of the roofing sheets.
In some circumstances, the bonding plates are placed over the top of the roofing sheets, while in other applications the bonding plates are placed under the roofing sheets. In either event, the subject fastening device is used to affix the roof sheets to the roof.
One of the predominant problems encountered with the use of nails or screws in fastening such bonding plates is that when they are inserted into the roof deck, they generally cause distortion damage in the wood or other roof material immediately around the screw or nail. Such distortion damage usually leaves gaps or spaces adjacent the screw or nails. This, in turn, causes weakness in the roof structure and also yields a potential source of roof leaks through the nail openings. This invention is therefore directed to overcome this problem and the following objects are directed accordingly.